/Engine/Source/Runtime/Core/Public/IO/IoDispatcher.h
Allows theIIoStoreWriterto avoid loading and hashing chunks, saving pak/stage time, as the normal process involved loading the chunks, hashing them, freeing them, making some decisions, then loading themagainfor compression/writting. It's completely fine for this to not have all available hashes, but they have to match when provided!
class IIoStoreWriterHashDatabase